[A case of lung cancer producing granulocyte colony-stimulating factor with a significantly high uptake in the bones observed by a FDG-PET scan].

A 57-year-old man complaining of right shoulder pain was admitted. Chest enhanced CT scanning showed a mass shadow in the right upper lobe with chest wall invasion. The laboratory data on admission showed marked leukocytosis. A CT-guided lung biopsy was performed, and a histological examination of the biopsy specimen showed a spindle cell type pleomorphic carcinoma. Immunohistochemistry staining using an anti-granulocyte colony-stimulating factor (G-CSF) monoclonal antibody demonstrated many tumor cells containing G-CSF as well as an increased level of serum G-CSF. The diagnosis was determined to be lung cancer producing G-CSF. FDG-PET scanning showed a significantly high uptake in the right upper field and the bones throughout the body. After chemoradiation therapy, the patient underwent a right upper lobectomy with a chest wall resection. Since then, the leukocytosis and the high level of serum G-CSF normalized and the high uptake in the bones disappeared in the FDG-PET scan.